The present invention relates to a connection tape for square hole-punched carrier tapes used in taping of surface mount electronic components, the connection tape being capable of connecting ends of square hole-punched carrier tapes in a simple and reliable manner, and a method for efficient manufacture of the connection tape.
According to conventional technologies, as shown in FIG. 7 and FIGS. 8(a), (b), electronic components to be surface mounted on a printed circuit board, such as resistors and capacitors, are generally taped on a square hole-punched carrier tape 1 in order to be supplied to an automatic mounting device.
This square hole-punched carrier tape 1 comprises a paper or plastic carrier tape 11 which includes sprocket holes 11a at a predetermined sprocket hole pitch and square pocket holes 11b at a predetermined pocket hole pitch, a top cover tape 12 adhered to cover the top of the pocket holes 11b without obstructing the sprocket holes 11a, and a bottom cover tape 13 adhered to cover the bottom of the pocket holes 11b. Each pocket hole 11b in the carrier tape 11 stores a surface mount component such as a capacitor (not shown) in consideration of its polarity and the like, with the component covered by the top cover tape 12 and the bottom cover tape 13 which are adhered over the top and bottom of the pocket holes 11b, respectively. In a mounting operation, the square hole-punched carrier tape 1, wound on a reel 14, is unwound from the reel 14 to be supplied to an automatic mounting device. While the top cover tape 12 is gradually peeled off from the carrier tape 11, the surface mount component stored in each pocket hole 11b is taken out by suction, etc. and mounted on the surface of a printed circuit board.
Thus, this type of square hole-punched carrier tape 1 is wound on and reeled out from the reel 14. The square hole-punched carrier tape 1 which has a predetermined length should be replaced with a new square hole-punched carrier tape 1, once a prescribed number of surface mount components have been mounted. Replacement of the used square hole-punched carrier tape 1 with a new one interrupts the mounting operation by the automatic mounting device, and seriously deteriorates its operational efficiency.
To cope with this problem, it has been proposed to connect the trailing end of a used square hole-punched carrier tape 1 to the leading end of a new square hole-punched carrier tape 1 by means of a synthetic resin adhesive tape, etc. Nevertheless, the adhesive tape fails to attach securely to both ends of the used and new cover tapes 12, or the adhesive tape sticks not only to the top cover tape 12 but also to the carrier tape 11. These incidents cause the top cover tape 12 to peel badly or the sprocket holes 11a to be blocked by the adhesive tape, ending in hindering the supply of the square hole-punched carrier tapes 1. Thus, there have been a lot of demands for a simple and reliable connection means which does not prevent smooth supply of the square hole-punched carrier tape 1.
In view of such circumstances, the present invention intends to provide a connection tape for square hole-punched carrier tapes which is capable of connecting used and new square hole-punched carrier tapes in a simple and reliable manner, without preventing smooth supply of the square hole-punched carrier tapes, and a rational method for manufacturing the connecting tapes.
A connection tape for square hole-punched carrier tapes (hereinafter simply called as connection tape) is used to connect the ends of the above-mentioned square hole-punched carrier tapes. The connection tape comprises a base tape whose top surface is subjected to a mold release treatment and which is provided with a slit extending approximately in a middle thereof and dividing the tape in half in the longitudinal direction, an adhesive tape whose bottom surface is an adhesive surface and which is adhered on the top surface of the base tape by the adhesive surface, and a protection tape whose bottom surface is an adhesive surface and which is adhered on the top surfaces of the base tape and the adhesive tape by the adhesive surface. At least the protection tape has a fold line which divides its width in half. The adhesive tape comprises a first adhesive tape which can adhere to the top cover tape, a second adhesive tape which can adhere over the top of the sprocket holes in the carrier tape without interfering with the top cover tape, and a third adhesive tape which can adhere to the bottom cover tape. The first adhesive tape and the second adhesive tape are disposed in a first half as sectioned by the fold line, with the second adhesive tape being closer to the fold line, and the third adhesive tape locates in line symmetry with the first adhesive tape about the fold line. At least the second adhesive tape includes a plurality of sprocket holes whose pitch and diameter is the same as that of the sprocket holes in the square hole-punched carrier tape.
Since this connection tape allows each half of the base tape to be peeled separately, the first halves and second halves of the first adhesive tape and the second adhesive tape can be sequentially attached on the top surfaces of the used and new square hole-punched carrier tapes. The third adhesive tape can be then attached to the bottom surfaces of the used and new square hole-punched carrier tapes by folding back the protection tape. Eventually, a pair of used and new square hole-punched carrier tapes are connected in a simple and reliable manner. Also, due to the second adhesive tape having the sprocket holes, the used and new square hole-punched carrier tapes, when connected, have their sprocket holes aligned in accurate continuation. Therefore, the used and new square hole-punched carrier tapes can be supplied in the connected state to the automatic mounting device, etc., without any incidence of trouble.
Besides, the first adhesive tape, the second adhesive tape and the third adhesive tape are attached to the top cover tape, the carrier tape and the bottom cover tape, respectively, in an independent and non-interfering manner. This helps to retain stable adhesion of the carrier tape to the top cover tape and the bottom cover tape. In a mounting operation, when the top cover tape and the bottom cover tape are peeled off from the carrier tape, they peel well without causing peeling failure at a connection point.
Additionally, in the connection tape of the present invention, a peeling portion subjected to a non-adhesion treatment is provided in a part of the vicinity of each end of the protection tape. Consequently, the protection tape can be easily peeled off after the adhesive tape is attached across the used and new square hole-punched carrier tapes.
In another aspect, the method for manufacturing connection tapes of the present invention comprises: a step of providing a long base tape whose top surface is subjected to a mold release treatment and which is provided with a slit dividing its width in half, adhering an adhesive surface of a long adhesive tape to the top surface of the long base tape, punching the long adhesive tape to give profiles of a first adhesive tape, a second adhesive tape and a third adhesive tape which together constitute an adhesive tape of the connection tape, and peeling off each punched scrap; a step of adhering an adhesive surface of a long protective tape on a top surface of a resulting two-layer continuous strip composed of the long base tape and the punched adhesive tape in order to form a three-layer continuous strip, punching the three-layer continuous strip to give a plurality of sprocket holes for the connection tape which penetrate at a position corresponding to the second adhesive tape, a plurality of perforations as a fold line of the connection tape and a plurality of perforations as a cut-off line between connection tapes, and removing scraps of the sprocket holes; and a step of cutting a resulting long continuous strip of connection tapes into a unit of predetermined. pieces of connection tapes to produce connection tapes in the form of a continuous sheet. This results in continuous and efficient manufacture of the connection tapes of the present invention.